1. Field of the Invention
Generally, the field of the present invention is laser patterning. More particularly, the present invention relates to the laser patterning of transparent conductive films.
2. Background
Strong demand for smaller and more portable computing devices has led to substantial innovation in many corresponding areas, including touch screens for smartphones and tablet computers. However, the path of innovation has not kept pace with manufacturing, particularly in the area of touch sensor patterning and printed electronics. Existing technologies, including photolithography, screen printing, and laser processing, suffer from poor takt (cycle) times due in part to the number of processing steps required. In addition to costs associated with poor cycle time, photolithographic and screen printing techniques include numerous drawbacks, including increased cost associated with expensive consumables and toxic waste.
Conventional laser processing techniques also suffer from numerous drawbacks. For example, laser beams are typically scanned across a target at great cost to cycle time. Moreover, in the processing of the targets the beams ablate away material which leaves visible or barely visible marks on the target. At least in the area of consumer products, it is highly desirable to process targets, such as touch screens, such that no visible effects are left on the surface at any angle or under any lighting conditions. In another serious drawback, and together with photolithographic and screen printing techniques, for flexible transparent substrates, a protective film must be removed prior to processing the substrate and reattached afterwards, leading to substantial further delay and increased processing expense. Thus, it is unfortunate that the current state of the art has yet to produce an efficient and superior technique for processing printed electronics and touch sensors on transparent substrates. Accordingly, there remains a need for a method for processing transparent substrates without the attendant drawbacks.